Ink-jet recording apparatus

摘要

A drive signal generating unit that generates a drive signal applying, in one pixel period, at least one drive waveform for causing ink droplets to be discharged can generate two types of drive waveforms, a large droplet waveform and a small droplet waveform. The large droplet waveform includes an expansion pulse expanding the volumes of pressure chambers and a contraction pulse making the volumes of the pressure chambers contract. The expansion pulse width of the large droplet waveform is 2.8 AL or longer but 3.4 AL or shorter. The small droplet waveform includes an expansion pulse, a pause period, and a contraction pulse, and the expansion pulse width of the small droplet waveform is 0.8 AL or longer but 1.2 AL or shorter, where AL represents a half of an acoustic resonance period of a pressure wave in the pressure chamber.

主权项

1. An ink-jet recording apparatus comprising:
a recording head that includes (i) a plurality of nozzles which discharge ink droplets, (ii) pressure chambers, each of the pressure chamber communicating with the nozzles, respectively, and (iii) a pressure generating unit which causes ink in each of the pressure chambers to be discharged out of the nozzles by varying volumes of the pressure chambers, respectively; and a drive signal generating unit that generates a drive signal for applying, in one pixel period, at least one drive waveform for causing the ink droplets to be discharged, wherein the ink-jet recording apparatus is configured to operate the pressure generating unit by applying the drive signal to the pressure generating unit to make the pressure generating unit cause the ink droplets to be discharged out of the nozzles, and wherein: the drive signal generating unit is configured to be capable of generating a large droplet waveform and a small droplet waveform, the large droplet waveform includes an expansion pulse to expand the volumes of the pressure chambers and a contraction pulse to contract the volumes of the pressure chambers, and an expansion pulse width of the large droplet waveform is not shorter than 2.8 AL and not longer than 3.4 AL, and the small droplet waveform includes, in this order, (i) an expansion pulse to expand the volumes of the pressure chambers, (ii) a pause period, and (iii) a contraction pulse to contract the volumes of the pressure chambers, and an expansion pulse width of the small droplet waveform is not shorter than 0.8 AL and not longer than 1.2 AL, where AL represents a half of an acoustic resonance period of a pressure wave in the pressure chamber.